Knee Replacement Flashcards Preview

Orthopaedics > Knee Replacement > Flashcards

Flashcards in Knee Replacement Deck (10)
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1
Q

What are the different types of knee replacement

A

Unicompartmental

Unconstrained bicompartmental

Constrained bicompartmental

2
Q

What is a unicompartmental knee replacement

A

Involves replacement of the medial or lateral tibiofemoral compartment only

Usually used for OA

Not suitable for patients with RA

3
Q

What is an unconstrained bicompartmental knee replacement

A

The articular surfaces of the knee are replaced by anatomically similar prostheses.

The femoral component is metallic

The prosthetic tibial plateau is made of polyethylene

It is the most common form of total knee replacement

4
Q

What is a constrained bicompartmental knee replacement

A

Marked bone loss and severe instability require the insertion of a prosthesis with a fixed hinge

5
Q

When are constrained bicompartmental knee replacements performed

A

Mainly used following wide resection of bone for cancer surgery (eg. osteosarcoma around the knee)

6
Q

What are the major disadvantages of constrained bicompartmental knee replacement

A

They are more prone to loosening or erosion of surrounding bone - due to lack of rotation causing severe shear stress on the femur and tibia

Revision of these knee replacements is difficult because of the amount of bone loss

7
Q

What are some contra-indications to knee joint replacement

A

Knee sepsis

Poor knee extensor function

Significant arterial disease

8
Q

Why would a patient get a total knee replacement as opposed to a unicompartmental knee replacement

A

Arthritis in two or all three of the compartments

9
Q

In unicompartmental knee replacements, which compartment is most likely to be replaced

A

Medial compartment

10
Q
A